I don't think "focus row on mouse hover" was what was asked for. At least I'm having exactly the same problem as the OP (on a Mac) and "focus on mouse row" doesn't help.
The problem is that the first click on the Sidewise window is ignored - it only serves to focus the window. Then you have to wait (so it's not a double click), then click again to actually switch tabs or otherwise interact with the window. Excel on Windows has the same problem. The fix would be to make the click that focuses the window actually be interpreted as a real click on the window as well. To capture and respond to all mouse events equally, regardless of whether the window has focus. I'm not sure how easy this is on OSX, but Chrome itself does it (ie. when the Sidewise window is in focus, any clicks on the Chrome window both focus the Chrome window and action the click), and every other app I've tried does too.
On a very related note, a similar problem is that when the Sidewise window doesn't have focus, mousing over the window does not cause the tab rows to highlight as it does when the window has focus. Again, when the Chrome window doesn't have focus, mousing over tabs does highlight the X buttons as expected, so it seems possible.
I don't think anyone wants the ability to mouse over the window and have it automatically switch tabs or something. I just want to not have to do an extra click to focus the window before being able to do anything with it.
I don't think "focus row on mouse hover" was what was asked for. At least I'm having exactly the same problem as the OP (on a Mac) and "focus on mouse row" doesn't help.
The problem is that the first click on the Sidewise window is ignored - it only serves to focus the window. Then you have to wait (so it's not a double click), then click again to actually switch tabs or otherwise interact with the window. Excel on Windows has the same problem. The fix would be to make the click that focuses the window actually be interpreted as a real click on the window as well. To capture and respond to all mouse events equally, regardless of whether the window has focus. I'm not sure how easy this is on OSX, but Chrome itself does it (ie. when the Sidewise window is in focus, any clicks on the Chrome window both focus the Chrome window and action the click), and every other app I've tried does too.
On a very related note, a similar problem is that when the Sidewise window doesn't have focus, mousing over the window does not cause the tab rows to highlight as it does when the window has focus. Again, when the Chrome window doesn't have focus, mousing over tabs does highlight the X buttons as expected, so it seems possible.
I don't think anyone wants the ability to mouse over the window and have it automatically switch tabs or something. I just want to not have to do an extra click to focus the window before being able to do anything with it.